AN ATR72 CREW AT TJSJ CLAIM THAT POOR TAXI SIGNAGE; POOR COCKPIT LIGHTING; AND AN INCOMPLETE 10-9 CHART CONTRIBUTE TO A TXWY INCURSION.

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THE EVENT OCCURRED DUE TO AMBIGUITIES IN THE TAXI CLRNC AND ARPT DIAGRAM. WE WERE GIVEN THE FOLLOWING TAXI INSTRUCTIONS FROM THE FRONT ROW OF GATE X AT TJSJ: 'TAXI TO RWY 10 VIA NOVEMBER ONE BRAVO.' I DEPARTED THE LINE AND TURNED TO THE RIGHT (E) TOWARD WHERE TXWY N1 IS DEPICTED ON THE ARPT DIAGRAM. I HAD SOME DOUBTS ABOUT THIS; BECAUSE THE TAXI CLRNC LEFT OUT THE TRANSITION FROM TXWY N1 TO TXWY B. IF I WAS TO TURN R IT SHOULD HAVE BEEN N1-N-H-B. IF I WAS TO TURN LEFT IT SHOULD HAVE BEEN N1-D-B. SINCE THE COCKPIT LIGHTING ON THE CAPT'S SIDE WAS ON MEL; I PASSED MY ARPT DIAGRAM TO THE FO; EXPLAINED MY INTENDED TAXI RTE AND ASKED HIM TO CONFIRM THAT I WAS GOING THE RIGHT WAY. HE LATER SAID THAT HE HEARD THE CLRNC AS; '...TAXI VIA NOVEMBER BRAVO.' (VICE N1) SO HE WAS SURE THAT I WAS CORRECT IN TURNING RIGHT. FACTORS CONTRIBUTING TO THE INCIDENT INCLUDE: AN UNCLR TAXI DIAGRAM. TJSJ PLATES 10-9 AND 10-9C CLRLY DEPICT N1 AS BEING NEAR GATES 9-17. THEY DO NOT CLRLY INDICATE THAT N1 EXTENDS WEST PAST GATE 1. THE STRIP OF TXWY BETWEEN HOLDING POINTS ONE AND TWO IS DELTA (AS DEPICTED). WE WOULD HAVE TO GO THROUGH IT DUE TO THE CLOSURE OF SIERRA. DUE TO THE ARPT LAYOUT; THERE IS NO ROOM FOR STANDARD SIGNAGE BETWEEN THE RAMP AND SIERRA; THEREFORE THERE IS NO ARPT MARKING AS TO THE PRESENCE OF N1 EXTENDING BOTH DIRECTIONS. IN OTHER WORDS; N1 IS AN UNMARKED TXWY. THE TAXI CLRNC LEAVING OUT INTERVENING TXWYS. MY DECISION TO MOVE THE ACFT WHEN THERE WAS STILL A SHADOW OF DOUBT IN MY MIND. THE LIGHTING MEL WHICH MADE IT VERY DIFFICULT TO SCAN THE ARPT DIAGRAM WHILE TAXIING. MY COPLT MISHEARING THE CLRNC AS VIA N WHICH WOULD UNQUESTIONABLY BE A RIGHT TURN. INSTALL PAVEMENT MARKINGS FOR TXWY N1. REVISE TJSJ ARPT DIAGRAMS (10-9/B/C) TO DEPICT THE E AND W EXTENTS OF TXWY N1. ATC USE OF STEREO TAXI CLRNCES AS THEY DO FOR GETTING FROM THE RWY TO GATES.